Objective: To investigate the risk factors related to incomplete excision after loop electrosurgical excision procedure (LEEP) in abnormal cervical cytology. Methods: This retrospective cohort study was performed during September 2010 to February 2017. The study population was patients with abnormal cervical cytology who treated by LEEP at Prapokklao hospital, Chanthaburi. From the medical records, data were collected include age, menopausal status, parity, body mass index, HIV infection, history of smoking, cervical cytology and characteristics of LEEP histopathology such as number of specimen, size and glandular involvement. Risk factors were investigated using multivariable risk ratio from risk ratio regression. Result: Five hundred cases of LEEP were done during this period and 322 cases were analyzed. Complete excision of the LEEP specimens found nearly half of the cases (46.9%). Multiple pieces of specimen was the risk factor for incomplete excision of LEEP (adjusted risk ratio [aRR] = 1.29, 95% confidence interval [CI] = 1.06-1.58; P = 0.013). Conclusion: The number of specimen from LEEP more than one piece was the risk factor for incomplete excision. Alternative methods such as cold knife conization (CKC), needle excision of the transformation zone (NETZ) or contoured loop excision of the transformation zone (C-LETZ) should be justified when all lesions could not be operated by single sweep.